Introduction

Following my first publication, I wanna talk about one of my favorite batting statistics, OBP or On Base Percentage. Hopefully after reading this you will get hooked up on OBP as I am :). I intend to cover what OBP means and measures, why it is a good statistic, where it fails, and why I think it is better than others basic ones, like avg (batting average) and slg (slugging percentage). So bear with me and let’s dive in to it.

On Base Percentage

If you like baseball and have watched Moneyball once in your life, you can probably skip this topic. If you don’t know baseball and have watched Moneyball because you saw Brad Pitt on the cover, this topic could be useful for you. Or if you are just here because I wrote something and you are supporting me, I love you. Now let’s talk OBP. As every percentage, we are talking about a ratio or as I like to call this, the ratio of how many times a batter has done something of value. This statistic is the percentage of how many times a batter got on base on merritt. The idea is simple, this is gonna tell you how many times the batter got on base safely or not. Meaning that if a batter has an OBP of 0.400 (or just .400), it means that 40% of the time the plate appearence was succesful, in other words, he did not generate an out.

Player value

If you have read my first article, you may be thinking, “wait, doesn’t batting average measure when the batter does something of value?”, and you are partially correct. I say partially because batting average hides somethings from you. The average not only gives the same weight to all of the hits (singles, doubles, triples and home runs), but it also makes two “mistakes”. First, it does not count walks and hit by pitches, which are scenarios where the batter gets on base safely and on merritt, and second, average is number of hits divided by at bats, not plate apparences, meaning that sacrifice flies (SF) are not taken into account. Ok, but how much those “mistakes” can change the statistics? Well, thanks to rotowire we can check it out.

year player avg median_avg
2015 Jose Bautista 0.250 0.2640
2018 Bryce Harper 0.249 0.2545
2019 Yasmani Grandal 0.246 0.2625
2016 Bryce Harper 0.243 0.2660
2017 Matt Carpenter 0.241 0.2670

Cheking their batting averages alone, their seasons seem like a waste of money. All of them had an avg under the median, meaning that at least 50% of the mlb players had a higher batting average than them. So if you try to find the value of those guys based on the avg, you won’t find it. So why did I choose them? Let’s ask Brad Pitt if he has something to say about these guys.

They get on base, people! But how often? We can check it out now!

These are the values of obp that were above 90% of the rest of the players that specific year. This means, for example, that in 2017, 90% of the players had an OBP lower than 0.3775 or 37.75%. So, only 10% of the players in mlb in 2017 got on base safely on merritt 37.75% or higher. Now let’s see my contenders.

Now that is something, huh? Four of them - with the fifth one pretty close, were in the top 10% in OBP. In other words, they generated an out fewer times than at least 90% of the mlb players! Isn’t that incredible? They got from a 0.25 or so batting average to a 0.37+ of OBP, just by walking!

Conclusion

No, OBP is not perfect. No, OBP will not give you the MVP (believe me, I tried), but I think it gives you a clear vision of some kind of a player’s performance, don’t you think? It gives you, with its own flaws, how often a player did something of value, not how often he/she got a hit, that is too sexy, it gives you how often a player did not generated an out, and that is the main goal, isn’t it? It shouldn’t matter how you step on first base safely, just get it done. If you do that, you may end up with a 20-game win streak.